Phytoplankton off Southern Coast of Ireland

A large, bluish-green phytoplankton bloom can be seen off the southern coast of Ireland, in the Celtic Sea. The bloom does not reach all the way to the coast itself, as is evident from the dark blue band of water just off the shoreline.

Phytoplankton are the autotrophic (food-producing) component of the plankton community and the most common kind of life present in the world’s oceans.

Like plants, they make energy through photosynthesis, and therefore need to be close to the surface of the water in order to receive enough sunlight.

Most phytoplankton are too small to be individually seen with the unaided eye. However, when present in high enough numbers, they may appear as a green discoloration of the water due to the presence of chlorophyll within their cells (although the actual color may vary with the species of phytoplankton present due to varying levels of chlorophyll or the presence of accessory pigments).